Solved issue #53

Solved 2 Xcode Compiler warnings for 64-bit architecture, by using correct data type NSUInteger instead of int:

1) MLPAutoCompleteTextField/NSString+Levenshtein.m:87:13: Implicit conversion loses integer precision: 'NSUInteger' (aka 'unsigned long') to 'int'

2) MLPAutoCompleteTextField/NSString+Levenshtein.m:88:13: Implicit conversion loses integer precision: 'NSUInteger' (aka 'unsigned long') to 'int'